A Review Study on Preventing and Detecting Technique of Black Hole Attack in MANET

There are basically two types of black hole attack i.e. internal black hole and External black hole attack. Black hole is a malicious node that wrongly replies for some route requests without having active route to particular destination and drop all the getting packets. If these malicious nodes work jointly as a collection then the damage will be very risky. This type of attack is called cooperative black hole attack. Black hole attack is a type of active attack. Black hole attack can arise when the malicious node on the path attack the data transfer and purposely drop, delay or change the data transfer passing through it. Black hole node treats itself as a trusted node. This is review study on Black hole node send false routing information, claim that it has a best route and cause additional good nodes to route data packets through the black hole node.


I. Introduction
With the fast growth of wireless method and expansion of computers, mobile computing has already become the field of computer communication in highly manner that include cell phones, laptop, handheld device [30]. Mobile ad hoc network is completely a wireless network that is very popular now days. Basically there are three types of wireless network that is ad hoc network, infrastructure network and hybrid network which is a combination of both networks [1]. An infrastructure network consists of wireless mobile device and one or more bridge, which attach the wireless network to the wired network. These bridges are called base stations. A mobile node within the network searches for the nearest base station (e.g. the one with the best signal strength), connects to it and communicates by it. The main fact is that all communication is taking place among the IJTSRD | May-Jun 2017 Available Online @www.ijtsrd.com that wrongly replies for some route requests (RREQ) without having active route to particular destination and drop all the getting packets. If these malicious nodes work jointly as a collection then the damage will be very risky. This type of attack is called cooperative black hole attack. Various factors affect the network performance:  Security Threats: In MANET, chances of attack are very high because of this open medium and infrastructure less feature [10].  Limited Bandwidth: mobile ad hoc network have less capacity than infrastructure network and in this chances of noise, interference is very high because of this bandwidth is very high.

II. LITERATURE SURVEY
In this we present an overview of earlier work related to mobile ad hoc network. Literature survey is the collection of available document on the topic which contains information, ideas, data and evidence written from a particular standpoint to accomplish certain aim or express certain views on the nature of the topic. Khin and Phyu.T (2014) discuss the impact of Black hole attack on AODV Routing Protocol. In this paper, we are simulating and analyze the impact of black hole attack on Ad Hoc On-Demand Distance Vector (AODV) protocol. The simulation is done by NS-2 and the simulation results are analyzed on various network performance metrics such as packet delivery ratio, normalized routing overhead and average endto-end delay [12].

ATTACK
AODV is an ad hoc on demand distance vector routing protocol that is work on the basis of demand of route when it is required by the source node to the destination node [1].AODV is improvement over Destination Sequence Distance Vector (DSDV) protocol. DSDV creating the small ad hoc network [11]. It requires universal distribution of connectivity information for right operation; it leads to frequent system-wide broadcast. so the size of DSDV ad-hoc networks is strongly restricted. When using DSDV, every mobile node also wants to maintain a whole list of routes for every destination within the mobile network. The benefit of AODV is that it tries to reduce the number of required broadcasts. It creates the route on an on-demand basis, as oppose to maintain a complete list of routes for each destination [11]. AODV does not maintain a routing table. When a node wants to communicate with another node, firstly a node sent a route request (RREQ) to the entire node in the network. All the middle node check whether it is the target node or it has a fresh route to go to the target node. If it is vacant, the middle node sends back Route Reply message (RREP) to the source node. Otherwise, it forwards the RREQ message to its neighbors by using flood approach.
This procedure is continuous until whether the destination node is found or the node that has a fresh enough route to the destination is found. Once finishing the route discovery process, the source node and the target node can be communicate and send the packets between them. When any node knows a link break or crash, Route Error (RERR) note is send to all other nodes [6]. Hello message is used for detecting and monitoring links to neighbors. Because of route error chances of attack is very high. Here we discuss the AODV Routing Protocol algorithm: Step1: Source node sent RREQ to all neighbors.
Step3: Source node select shortest and next shortest path based on the number of hops Step4: Source node checks its routing table for single hop neighboring nodes only Step5: If the neighbor node is in its routing table then sent data packet else. The node is malicious (black hole) and sends fake packets to that node.
Step 6: Invoke the route discovery notify all the neighboring nodes about the outsider.
Step 7: Add the status of outsider to the routing table of source node.
Step 8: Again send packet to neighboring node Step 9: If step 5 repeats then broadcast the malicious node as black hole Step 10: Update the routing table of source node after every broadcast Step 11: Repeat step 4 to 10 until packet reaches the destination node correctly.
Black hole attack is a type of active attack [4]. Black hole attack can arise when the malicious node on the path attack the data transfer and purposely drop, delay or change the data transfer passing through it [9]. Black hole node treats itself as a trusted node. Black hole node send false routing information, claim that it has a best route and cause additional good nodes to route data packets through the black hole node. A IJTSRD | May-Jun 2017 Available Online @www.ijtsrd.com black hole node drops all packets that it receives instead of normally forward those packets or message. There are basically two types of black hole attack i.e. internal black hole and External black hole attack [5]. Black hole is a malicious node that wrongly replies for some route requests (RREQ) without having active route to particular destination and drop all the getting packets. If these malicious nodes work jointly as a collection then the damage will be very risky. This type of attack is called cooperative black hole attack.

Internal Black hole attack
In this attack, malicious attack does not try to fit in to active route between source and destination [5]. It is present internally in the network, makes itself active route node in the network [3]. It will be able to attack as the data transmission start between nodes [5].

External Black hole attack
In this, malicious node is externally to the network and stay outside [3]. It creates congestion in the network and disturbs all the working of the network [3]. It can become an internal attack when it take control of internal malicious node and run it to strike other nodes in network [8].
Single Black hole attack In this attack, single node is behaving as a black hole node and disturbs the entire network functioning [6]. There is only one single node in an area [12]. AODV route discovery method is based on RREQ/RREP messages. Source node broadcast the RREQ message to all its neighbors. Either the target or middle node sends RREP (route reply). The RREP received first by source node is accepted and all further RREPs are not needed. Black hole node takes benefit of this characteristic of AODV and sends RREP (route reply) without checking its routing table. In this way, a route through black hole node is setup and black hole node consumes all the packets and drops all the packets [7].

Route Discovery
Route discovery is the mechanism by which source node discovers route for destination. In route discovery, the source node floods the route request packet throughout the network, and the reply is returned either through the destination node or through any intermediate nodes which contains the route to destination in its route cache. For example, if source Node A wishes to send packet to Destination Node B, it obtains a source route for Node B. This route discovery is initiated only when Node A tries to send packet for Node B and does not find any route in its own route cache. Finding a route for destination will be purely on demand using the route discovery mechanism.

VI. CONCLUSION AND FUTURE SCOPE
This is a review on various protocols standards. In this paper we describe the brief introduction to the many challenges in black hole prevention techniques in MANET. Algorithms that are described in are based on comparison of AODV and DSDV .Wireless networks are characterized by a lack of infrastructure, and by a random and quickly changing network topology; thus the need for a robust dynamic routing protocol that can accommodate such an environment.
We have described many of the issues that need to be tackled and that have been left unspecified by the current standards. We identified a number of objectives that any solution should aim at meeting and provided an initial investigation of some of these problems. This is obviously preliminary work and we are actively investigating many of the problems outlined in this paper. We hope that the paper will also entice others in exploring what we feel is a promising and rich research area. After removing this attack from network, it will increase the packet delivery Ratio and decrease the packet dropping ratio and increase the security from black hole attack. In future, we try to more improve the MN-ID method which gives better results.